展开 (ax+by)(c+dy)

解答

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(a x + b y) (c + d y)

a c x + a x d y + b cy + b y d y

求解步骤

(a x + b y) (c + d y)

使用 FOIL 方法:

(a + b) (c + d) = a c + a d + b c + b d

a = a x, b = b y, c = c, d = d y

= a x c + a x d y + b yc + b y d y

= a c x + a x d y + b cy + b y d y

e x p an d (a^{\frac{9}{2}} - b^{\frac{9}{2}})^{2}

s im pl i f y (sin (x))^{2} + (6 + cos (x))^{2}

e x p an d (x^{2} + y^{2} + 1) \frac{d x}{d y}

e x p an d \frac{12 x ^{2} - 31 x + 4}{( x - 4 ) ( x ^{2} + 2 )}

s im pl i f y (x + 4 - 1)^{2}